The generation of 3D/4D volume rendered images from data collected by medical imaging devices has become increasing popular as a method for improving medical visualisation. Such techniques can be applicable to a variety of medical imaging methods such as, but not limited to, ultrasound imaging, MRI, CT, PET and the like.
For example, ultrasound scanning that uses transmission and reception of sound waves from a transducer can be used to image structures inside the body. The imaging of a fetus within the womb is a well-known example of the use of this technique.
Three-dimensional (3D) ultrasound images can be generated by using software to combine ultrasound data that has been taken at different positions or angles, and to render an image from the combined data using methods such as simple surface shading or direct volume rendering. In four-dimensional (4D) ultrasound imaging systems, a series of three-dimensional images obtained at different times is dynamically rendered to produce a moving 3D image, for example, a 3D ultrasound movie.
In recent years, 3D and 4D ultrasound images have been made more photorealistic through the use of advanced lighting and rendering techniques (such as global illumination, gradient free lighting, subsurface scattering or photon mapping) that simulate illumination of the imaged object from a particular angle.
Selection of optimal rendering parameters, such as light position, colour map, brightness, radiosity, and the like, can have a significant impact on the quality and realism of the rendered images derived from the data collected by the medical imaging devices. However, many operators of medical imaging devices do not have the time or expertise in rendering techniques to explore and select the optimal rendering parameters for a particular imaging situation and the interfaces of some medical imaging systems may not be as intuitive as users would like.